HomeNews & TopicsHealth Care PolicySalt-coated masks and air filters to potentially slow the spread of COVID-19

Salt-coated masks and air filters to potentially slow the spread of COVID-19

Published on

By Deba Hafizi

The latest potential safeguard to prevent the spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus that causes COVID-19, can be found in almost every kitchen pantry — salt! Canadian and international researchers are examining whether coating masks, air filters, and high-touch surfaces with sodium chloride (salt) might help prevent the spread of SARS-CoV-2 and other viruses and bacteria.

In a recent issue of Health Technology Update, CADTH looked at the latest research on compressed salt surfaces for reducing the transmission of viruses and bacteria. CADTH is an independent agency that finds, assesses, and summarizes the research on drugs, medical devices, tests, and procedures. The CADTH Health Technology Update newsletter describes new and emerging health technologies that are likely to have a significant impact on health care in Canada.

Salt is a natural substance that inhibits the growth of bacteria and has long been used in food preservation, flavouring, pharmaceuticals, agriculture, and at-home remedies. The theory behind salt’s potential ability to inhibit SARS-CoV-2 is that when droplets containing virus particles encounter a salt-coated surface, the water in the droplets dissolves some of the salt. When the water evaporates, the salt recrystallizes and the jagged salt crystals pierce the virus membrane, ultimately killing it. This method has been tested against influenza viruses and bacteria and has been proven to be effective. Compressed salt is therefore being investigated as an antimicrobial for use on high-touch surfaces — such as door push plates, bed rails, and taps — by an Alberta company, Outbreaker Solutions Technologies. Pilot evaluations of Outbreaker products (compressed salt-coated surfaces) have been carried out at several Alberta facilities. A 2016 pilot study found that a compressed sodium chloride surface reduced contamination with the methicillin-resistant Staphylococcus aureus (MRSA) bacteria by 94 per cent within the first 60 seconds compared with 71 to 73 per cent for copper surfaces. Outbreaker is currently investigating whether these salt-coated surfaces will have a similar impact against SARS-CoV-2.

Other salt-related developments are also underway, including salt-coated facial masks and air filter materials, as well as a saltwater soaking solution for household materials and cloth masks. A team from the University of Alberta found that salt-coated facial masks effectively deactivated influenza virus aerosols and bacteria bio-aerosols and is currently investigating whether it will also protect against SARS-CoV-2, which has a similar morphology to other tested viruses. Elsewhere, a research team in Boston investigated whether saltwater-soaked materials — such as paper towels and surgical masks — were able to filter out particles the size of viruses in droplet testing. The investigators found that there was a decrease in bacterial growth on masks they had contaminated with E. coli, especially in portions with higher salt saturation. These findings suggest that salt-water treated kitchen paper towels could be an inexpensive and accessible way to add additional layer of protection for people wearing homemade cloth masks or for health care workers who need to extend the life of their personal protective equipment, or PPE.

While these technologies show promise, they have not been tested against SARS-CoV-2 nor have they been vetted or recommended by any federal or public health authorities for use on surfaces or facial masks.

While salt may have antimicrobial properties when applied to surfaces and materials, this doesn’t mean that injecting it or spraying it up the nose can prevent or cure COVID-19. Much like bleach, which has antimicrobial properties and is used on everyday surfaces in your home, it does not mean it will have the same effect in the body; in fact, ingesting bleach can be harmful! Salt, on the other hand, is generally safe for consumption and is often found in your favourite dishes, however, at high temperatures it can produce a vapor that is an eye irritant, and ingesting high doses can be toxic to humans and animals.

While there is currently no evidence that certain surfaces or surface coatings can halt or inhibit the growth of SARS-CoV-2, Health Canada has compiled a list of hard-surface disinfectants with evidence against the virus. Investigation of new technologies continues as we learn more about the virus. As schools and public spaces re-open, increasing the effectiveness of masks and antimicrobial surfaces could be a positive preventive public health intervention.

For more information, read the Health Technology Update newsletter at cadth.ca/health-technology-update-issue-27-0. If you’d like to learn more about CADTH, visit cadth.ca, follow us on Twitter @CADTH_ACMTS, or speak to a Liaison Officer in your region: cadth.ca/Liaison-Officers. To suggest a new or emerging health technology for CADTH to review, email us at HorizonScanning@cadth.ca.

Deba Hafizi is a knowledge mobilization officer at CADTH.

Latest articles

Common drug interactions with over-the-counter medications

TJ, a 45-year-old male with symptoms of a common cold (sore throat, headache, runny...

Easing the Transition to the Cloud. Modernizing made simple with integration support.

Across Canada, most hospitals and healthcare authorities recognize the need to modernize their systems....

Rovolutionizing geriatric care: Meet Canada’s leading Universal Health Hub (UHH)

Universal Health Hub (UHH) is the only Health Care Organization in Canada which is...

National efforts to guide safe, effective, and equitable use of opioids for quality pain management in children

No one should experience untreated pain. Yet, in Canada, two out of three children...

More like this

Wait times in healthcare often linked to diagnostic testing – adding more doctors and nurses alone won’t improve that bottleneck

There is an emerging consensus that Canada’s healthcare system is in crisis.  Stories appear in...

Physician work hours, especially for male doctors, have declined since 1987

Physicians in Canada, especially male physicians, are working fewer hours than they did three...

No longer just tobacco and opioids: B.C. plans commencing more class actions to recover health care costs involving virtually any product

On March 14, 2024, the province of British Columbia proposed broad multi-government class action...

Wait times in EDs are nothing new – and that’s the problem

The respiratory virus season is upon us, and those working in the emergency departments...

Ontario hospitals play critical role in Canadian health care advancements and innovation

Twenty Ontario research hospitals have been celebrated for their excellence in health research and...

Too much paperwork is hurting physicians, and health care

Few of us look forward to administrative tasks. For physicians, however, relentless paperwork is...